idea.h

IDEA加密算法属于数据块加密算法(Block Cipher)类。IDEA使用长度为128bit的密钥

#ifndef IDEA_H
#define IDEA_H

/*
 *	idea.h - header file for idea.c
 */

/* typedefs for BYTE, WORD16, boolean, etc. */
typedef unsigned char boolean;	/* values are TRUE or FALSE */
typedef unsigned char BYTE;	/* values are 0-255 */
typedef BYTE *byteptr;	/* pointer to BYTE */
typedef char *string;	/* pointer to ASCII character string */
typedef unsigned short WORD16;	/* values are 0-65535 */
typedef unsigned long WORD32;	/* values are 0-4294967295 */

#ifndef TRUE
#define FALSE 0
#define TRUE (!FALSE)
#endif	/* if TRUE not already defined */

#ifndef min	/* if min macro not already defined */
#define min(a,b) ( (a)<(b) ? (a) : (b) )
#define max(a,b) ( (a)>(b) ? (a) : (b) )
#endif	/* if min macro not already defined */

/* end typedefs for BYTE, WORD16, boolean, etc. */

#define IDEAKEYSIZE 16
#define IDEABLOCKSIZE 8

#define IDEAROUNDS 8
#define IDEAKEYLEN (6*IDEAROUNDS+4)

#define MAX_PATHLEN 256
#define KBYTES 1024

/*
 * iv[] is used as a circular buffer.  bufleft is the number of
 * bytes at the end which have to be filled in before we crank
 * the block cipher again.  We do the block cipher operation
 * lazily: bufleft may be 0.  When we need one more BYTE, we
 * crank the block cipher and set bufleft to 7.
 */
struct IdeaCfbContext
{
	BYTE iv[8];
	WORD16 key[IDEAKEYLEN];
	int bufleft;
};

struct IdeaRandContext
{
	BYTE outbuf[8];
	WORD16 key[IDEAKEYLEN];
	int bufleft;
	BYTE internalbuf[8];
	BYTE timestamp[8];
};

////////////////////////////////////////////////////////////////////////////
static void ideaCipher(BYTE const (inbuf[8]), BYTE (outbuf[8]), WORD16 const *key);
int EncryptFile( char *szSrcFile, char *szEncFile, BYTE *UserKey );
int DecryptFile( char *szSrcFile, char *EncFile, BYTE *UserKey );

////////////////////////////////////////////////////////////////////
void ideaCfbReinit(struct IdeaCfbContext *context, BYTE const *iv);
void ideaCfbInit(struct IdeaCfbContext *context, BYTE const (key[16]));
void ideaCfbDestroy(struct IdeaCfbContext *context);
void ideaCfbEncrypt(struct IdeaCfbContext *context, BYTE const *src, BYTE *dest, int count);
void ideaCfbDecrypt(struct IdeaCfbContext *context, BYTE const *src, BYTE *dest, int count);
void ideaRandInit(struct IdeaRandContext *context, BYTE const (key[16]), BYTE const (seed[8]), WORD32 timestamp);
BYTE ideaRandByte(struct IdeaRandContext *c);

#endif /* !IDEA_H */